The diaphragm and lubricant gel for prevention of cervical sexually transmitted infections: results of a randomized controlled trial.
BACKGROUND
We evaluated the effectiveness of the Ortho All-Flex Diaphragm, lubricant gel (Replens) and condoms compared to condoms alone on the incidence of chlamydial and gonococcal infections in an open-label randomized controlled trial among women at risk of HIV/STI infections.


METHODS
We randomized 5045 sexually-active women at three sites in Southern Africa. Participants who tested positive for curable STIs were treated prior to enrollment as per local guidelines. Women were followed quarterly and tested for Chlamydia trachomatis (CT) or Neisseria gonorrhoeae (GC) infection by nucleic-acid amplification testing (Roche Amplicor) using first-catch urine specimens. STIs detected at follow-up visits were treated. We compared the incidence of first infection after randomization between study arms in both intent-to-treat (ITT) and per-protocol populations.


RESULTS
Baseline demographic, behavioral and clinical characteristics were balanced across study arms. Nearly 80% of participants were under 35 years of age. Median follow-up time was 21 months and the retention rate was over 93%. There were 471 first chlamydia infections, 247 in the intervention arm and 224 in the control arm with an overall incidence of 6.2/100 woman-years (wy) (relative hazard (RH) 1.11, 95% Confidence Interval (CI): 0.93-1.33; p = 0.25) and 192 first gonococcal infections, 95 in the intervention arm and 97 in the control arm with an overall incidence of 2.4/100wy (RH 0.98, 95%CI: 0.74-1.30; p = 0.90). Per protocol results indicated that when diaphragm adherence was defined as "always use" since the last visit, there was a significant reduction in the incidence of GC infection among women randomized to the intervention arm (RH 0.61, 95%CI: 0.41-0.91, P = 0.02).


CONCLUSIONS
There was no difference by study arm in the rate of acquisition of CT or GC. However, our per-protocol results suggest that consistent use of the diaphragm may reduce acquisition of GC.


BACKGROUND
ClinicalTrials.gov NCT00121459.
Ramjee
Gita
G
Medical Research Council, Durban, South Africa. ramjeeg@mrc.ac.za
van der Straten
Ariane
A
Chipato
Tsungai
T
de Bruyn
Guy
G
Blanchard
Kelly
K
Shiboski
Stephen
S
Cheng
Helen
H
Montgomery
Elizabeth
E
Padian
Nancy
N
D000328:Adult; D002690:Chlamydia Infections / Q000517:prevention & control; D002692:Chlamydia trachomatis / Q000302:isolation & purification; D017280:Condoms; D003274:Contraceptive Devices, Female / Q000592:standards*; D004269:DNA, Bacterial / Q000652:urine; D005260:Female; D006069:Gonorrhea / Q000517:prevention & control; D006801:Humans; D015994:Incidence; D054327:Lubricants / Q000592:standards*; D008875:Middle Aged; D009344:Neisseria gonorrhoeae / Q000302:isolation & purification; D012749:Sexually Transmitted Diseases / Q000517:prevention & control*; D013019:South Africa; D016896:Treatment Outcome; D055815:Young Adult
D004269:DNA, Bacterial; D054327:Lubricants